In Terra Mystica, many (but not all) experienced players find the game to present more interesting decisions when the factions are spaced out around the color wheel. This is a core part of the central tension of the game. So it would be enjoyable for many to have a setting choice for both player-selected auctions and random faction selection that would cause it to be impossible for there to be three color-adjacent factions in a row. That is, no "sandwiched" factions when this setting is turned on.

I believe this would be used quite often by a sizable portion of the player base. Auctions are an important part of the modern Terra Mystica game as it allows players to have a greater feeling of freedom of choice compared to turn-order selection. However, one side effect of auctions is the possibility of placing three adjacent factions that greatly impair each other, making the fourth faction 30 or more points better. In such cases, the game feels to some people less enjoyable than games without such "sandwiched" factions. This setting proposal would allow those who prefer to play auction games without such worries.

Im totally supporting this suggestion. Also might be useful: i believe the current game already have a logic for non sandwiched factions that is used when you chose Random Factions. Or at least i have never seen it generate random factions that would be sandwiched.
So if thats the case, this feature would mean just to add an option to game settings, and the logic is (maybe is) already implemented.